This invention relates to a coiled filter element configured for axial flow and to a filter system which utilizes such a filter element.
U.S. Pat. No. 6,322,602 discloses an air filter having a filter element through which air flows axially arranged in a cylindrical filter housing. The receptacle space for receiving the filter element in the filter housing is closed by a housing cover on one axial end face in the area of the oncoming flow side of the filter. This cover is detached to enable replacement of the filter element, whereupon the filter element is removed axially from the receiving space and can be replaced by a new filter element.
This embodiment has the disadvantage that in order to replace the filter element, the housing cover in the oncoming flow area must be removed, which initially requires dismantling the entire filter housing from its installed position, because the housing cover is connected to the inlet lines for supplying the air to be cleaned. Therefore, the filter element can be replaced only with a great deal of effort, which lengthens the time required for the maintenance and results in high maintenance costs.
Furthermore, WO 2004/020075 proposes a filter system for the intake air of an internal combustion engine in particular. This filter system comprises a housing with at least two housing parts and a filter element comprising a coiled filter, in which the housing parts can be separated in the area of the fastening of the filter element. The coiled filter has a profiled gasket on its circumference, which profiled gasket consists of an elastic band designed in the form of a bead-shaped bulge. The two housing parts can be clamped over this bulge.